Users have recently used more and more data in wireless communication systems. In spite of increasing capacity and throughput of mobile communication systems, network congestion still takes place according to users' manners, regions, and time zones in using mobile communication. For example, if a large number of individual users requesting a service consuming much radio resources are concentrated in a specific cell, network congestion may occur. The network congestion may be more highly likely to occur in the daytime than at night. The network congestion may be an obstacle to a new user's access to a network or provisioning of a requested service to an individual user.
Various techniques are under discussion to control network congestion. Conventional congestion control schemes are based on solutions such as differential support of a specific user, a specific bearer, or a specific Internet Protocol (IP) flow according to a specific priority level. In this case, some users may not receive a service for a long time (this may be called radio resource starvation).
Particularly, if handover occurs due to movement of a user, the starvation problem may not be overcome. In a Core Network (CN)-based congestion control scheme, even though handover occurs in a Radio Access Network (RAN), a management node of a CN is not changed and thus congestion control may be possible. However, a conventional RAN-based congestion control scheme does not overcome the starvation problem during handover.